1. Field of the Invention
The present invention relates to an integrated unit performing a plurality of functions related to air treatment in pneumatic systems.
2. State of the Prior Art
Practically all pneumatic systems using compressed air for actuation functions of every type start with a unit for treatment of the compressed air. In fact, the air before being admitted into the distributors and actuators is required to be regulated and filtered. Therefore, these units are applied to all working machines, such as assembling machines, machine tools, packaging machines, etc.; in the compressed-air distribution systems, in the car field, in particular in equipped lorries, in the industry field, etc.
All known units consist of individual elements, each having a specific function, that are then assembled in series with each other. The most traditional combination of elements used in automation may comprise a manual on-off valve at the inlet, a filter, a pressure regulator, an electric on-off valve, a pressure switch, several intakes, etc.
The elements can be someway of the modular type so as to have attachments and sizes compatible with each other in the same series, but in any case they are always elements that must be assembled one after the other.
There are many limits and defects in the units made with known elements. It is to be mentioned the big sizes, in particular with a high extension in the formation direction of the series; the very bad ergonomics due to the fact that the functions of interest of the user or the maintenance man are distributed in an incoherent manner on the unit, some on the upper side (the pressure regulating hand grips, for example), some on the front (manometer, etc.), some on the lower side (filter cup), so that there are not only positioning difficulties but also a poor understanding of the functions performed by each element and of the point which must be acted upon for regulations; the difficulties for servicing interventions, such as replacement of the filter cartridge; the very bad overall aesthetic appearance that is no longer suitable for the modern machines for which the units are designed.
In addition, some functional problems are still unresolved, so that the reliability of the system as a whole is impaired due to leakages, jamming, etc.
For example, in known filter modules or elements the servicing interventions, such as replacement of the filter cartridge, are difficult and often uncomfortable, above all when the unit is positioned in regions of the machine utilizing it that are hardly accessible. In particular, in order to receive the condensate at the filter base, the cartridge is always disposed vertically in a cup under the air inlet, with the air flow that is radially directed from the cartridge outside to the inside. Such an arrangement creates problems in terms of vertical bulkiness that can be hardly resolved, so that uncomfortable operations are required even if the filter cup is only to be unscrewed.
In addition, the automatic systems for condensate discharge are subjected to jamming in the presence of solid particles suspended in the air and therefore they are often refused by the user.
It is a general aim of the present invention to obviate the above mentioned drawbacks by providing an innovative integrated unit enabling supply of the different facilities that are necessary at the inlet of pneumatic systems and, among other things, possessing features of small bulkiness, high reliability, practical and quick use and ready maintenance.
It is a further aim of the present invention to provide said unit with a filtering device equipped with an efficient and easily accessible filter, above all for the operations concerning maintenance and replacement of the cartridge and that, if also equipped with a device for condensate discharge, does not suffer for jamming due to the presence of solid particles entrained into the device by the air flow.
A still further aim of the present invention is to provide the unit with a regulation device for progressive starting that is of reduced bulkiness and is capable of offering a satisfactory progressive starting irrespective of the conditions of the circuit downstream thereof.